A light-emitting device of current confinement structure has been realized having an increased output and a high speed characteristics, and in order to confine the emitting region of in a light-emitting device, this device has been provided a current blocking layer which has a high resistive region etc. and increases the carrier densities of a part of an active layer.
In order to make the output higher and the response more higher of the light-emitting device of current confinement structure, a vertical resonator type of light-emitting device is used having a resonator structure that causes light to resonate and with a current confinement structure to increase the current density of the active layer.
As a technique to fabricate the current confinement structure in a light-emitting device, there have been known, e.g., ion implantation, impurity diffusion, selective oxidation and burying methods.
Patent Reference 1 discloses a light-emitting device having a current confinement structure of a high resistant area that is formed by implanting accelerated hydrogen (H) ions into the light-emitting device from surface or side face thereof. In this ion implantation method, damages have been introduced to crystal by this method and the reliability was deteriorated.
Patent Reference 2 discloses a light-emitting device having a current confinement structure in which a current conducting area is provided by implantation of zinc (Zn) ions from a surface of the device and diffusing them into a high resistance area to inverse its conduction-type. In this impurity diffusion method, the concentration of carriers in the region of an active layer has been changed when electrically conducting so that the light output has been unstable, since the impurity that has a large diffusion coefficient has been diffused.
Patent Reference 3 discloses a light-emitting device of a current confinement structure which is fabricated by oxidizing a layer that is large in percentage composition of aluminum (Al) from a side face of the device when heat treated in a water vapor atmosphere. In this selective oxidation method, the control of the oxygen content was difficult. Since the layer of high Al content has been changed its volume and the distortion was introduced to the crystal, the reliability was deteriorated.
Patent References 4 and 5 disclose a light-emitting device of a current confinement structure in which a current blocking layer is locally buried in the device using a forbidden band gap barrier of pn junction. Further, Patent Reference 5 discloses a light-emitting device having an etching stop layer.    Patent Reference 1: JP 3638515 B    Patent Reference 2: JP 2001-44501 A    Patent Reference 3: JP 2003-8142 A    Patent Reference 4: JP 3406907 B    Patent Reference 5: JP H05-175615 A